Not sure what specific model you're referring to, but AFAIK:
Single-pole (two-wire) line thermostats directly control the amount of power delivered to the heating element, e.g. by killing parts of the sine wave, and "steal" their own operating power from it. They aren't designed for indirect control.
Two-wire low-power (24V) thermostats work as a simple switch to signal a heat call to the heater (why a mercury ball works). If they need power for operation, they draw it either from a third (C) wire or batteries. I've heard of power-stealing units (Nest?) but whether they work or not would totally depend on the specific heater's specs.
Actually some line voltage thermostats also have a mode for use with forced air in wall 120V / 240V heaters and will act just like a regular solid state relay instead of modulating the sine wave..
Honeywell Home CT30A1005 Standard Manual Economy Thermostat - Heat Only
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@HarleysWorld You never said, but if control is low voltage open/closed type, then this in parallel with a zigbee or z-wave relay should allow control and freeze protection.
Reviving an old thread for some advice. I am trying to find a reasonably priced 2 wire zigbee or zwave thermostat to replace the on/off switch that controls my gas fireplace. I assume it is a 24 volt low voltage situation as it simply turns the fireplace on or off. The Honeywell seems to work but pricey at over $200, I can't seem to find a Sinope model that will work with a 2 wire installation (with batteries).
Question for the Community, any other suggestions for smart control of a Gas Fireplace?
hmm are you sure about this, I would message them to make sure, in the instructions they do not mention 2 wire wiring. @Locutus, if you message them to confirm this, please report back their answer.
You actually need to check a box before adding to your cart!
This is their Low VOltage Thermostat:
They do technically sell a 2 wire Zigbee thermostat, but it specifcally states that it is for electric baseboard heaters, so not clear if this compatible for a Low Voltage setup.
I knew I saw it somewhere, but could remember where exactly.
Those are for 120V/240V baseboards only
Most likely your fireplace only needs a dry contact, in that case you might be able to use the TH1400ZB model, but you will need a 24VAC supply and a 24VAC relay to make the contact for the fireplace. Unless you are very confortable with electricity and all that stuff, I would recommend getting someone in the HVAC field to come out and check your setup.
I have three of those. I used them with two wire heat, with a c-wire, but they also run on 4AA batteries. They have tons of options for multi-stage heating, AC, etc, but just connecting the two heating wires will work fine for OP, if it is a low voltage thermostat, like 24VAC.
Any thermoset with only the two heating wires connected to it becomes a 2-wire thermostat. However, I thought floor heating was almost always high voltage, in which case the T6s would not work.
Edit: Since it is boiler floor heat, and not electric, OPs thermostats are most likely 24VAC.
Ah, I think the link took me to the top of the page. My bad.
However, I think the T6 use case here still applies. I got my T6s used on Ebay, three of them for about $100. I see now that there are several used ones for around $60 listed on Ebay now.
Thanks all for the replies, and yes...I kind of hijacked this old thread since it was very close to my use case
I will report back with what I hear from Sinope.
Indeed the Honeywell will certainly work, but retails for over $200 in Canada. I do see the ones on eBay but they are all shipping from the US, not sure how that works with customs / duty and such.
Thanks all for the suggestions, here is a summary:
Centralite Pearl - looked promising, found an Amazon Page but showing "Currently Unavailable", can't find a retailer in Canada that sells it
Honeywell T6 Pro - will work, but pricey ($200 CAD), way more features than I need.
Ezlo Series 800 Z-Wave - a bit cheaper than the Honeywell at $180. (I was poking around on the Centralite website and I ended up on an Ezlo site...not sure what is going on there)
Ecolink Zigbee TBBZ500WH - checks the boxes, comes in at $160, will probs try this assume it will work with the generic driver
Thank you for the summary Do let me know what you end up with! I'll try to find that Centralite Pearl here in the US and will let you know thoughts on it. Oh also, see if you can get in eBay. This seller has like 36 of them, but not sure if ships to Canada: Centralite 3-Series Pearl Touch Thermostat for sale | eBay. Turns out I have one of these sitting upstairs that I was also planning on installing for our AC. I'll try installing it to one of the thermostats for our boiler system first and let you know how it does!
Ok, one more option! Earlier in the thread someone suggested a Zen zigbee thermostat and I really liked the sleek look of it (since it is going in my Living Room). I had originally discounted this one since the retail cost is over $270 on Amazon, but then I looked on eBay and found a seller that is selling them from Canada. I pulled the trigger and will report back when I get it up and running!
I was not crazy about an eBay seller coming from the US, most will ship to Canada, but the Duty and Customs costs can be a crap shoot (sometimes and extra 50$-70$ with brokerage fees, etc.),
Got the Zen thermostat up and running and so far so good. The wiring was not straightforward since a remote on / off switch does not really follow any colour coding standards. My 2 wires were Black and White so I hooked the Black to Rh and White to W on the unit. Connected it up with my Google Community app and can now say "hey Google, set the fireplace to 21 degrees" and it responds.
The only thing I can't seem to figure out is how to set the mode (which is basically Heat or Off). I can do it on the unit but when I try from the Hubitat Device page it ignores. I was hoping to use the mode to simply turn on and off, but I can't seem to do that other than walking up to the unit and turning it off. I suppose when the device is configured as 2 wire heat only it probably no longer accepts Mode commands.
